Water heater



FIG. 1 is a perspective view of the water heater showing our new design.

FIG. 2 is a top view of the water heater shown in FIG. 1.

FIG. 3 is an elevation view of the water heater shown in FIG. 1; and,

FIG. 4 is a front view of the water heater shown in FIG. 1. 

We claim the ornamental design for a water heater, as shown and described in the figures. 